Commercially available programmable logic controllers (PLC's) can be supplied with a memory device for storage. The memory device, which can be a memory cartridge, is most often an electronically erasable programmable read only memory (EEPROM) device. Common methods of using the memory cartridge include the storage of PLC configuration and programming information.
U.S. Pat. No. 5,727,170 (Mitchell) allegedly cites: “[t]he PLC has a user configurable protocol port attached thereto. Briefly stated, at the PLC communication port or as a result of a user program or input/output I/O event, a special flag bit may be set which thereby allows the communication port to be activated. This is done by the flag bit causing an interrupt to occur in the PLC user program which allows a user to communicate with a user specified protocol scheme rather than the normal communication/programming protocol when this special bit is not set.” See Abstract.
U.S. Pat. No. 5,485,590 (Hyatt) allegedly cites: “[a] module interfaces a programmable controller to several serial communication networks over which data may be exchanged according to different protocols. A module has a central controller and a separate port circuit for each of the networks. Each port circuit includes a microprocessor and a shared memory to which both the central controller and the port microprocessor have access for the exchange of data. The central controller transfers data from the shared memories to a module output coupled to other components of the programmable controller. A removable memory cartridge stores a plurality of programs for execution by the port microprocessors to exchange data over the networks using different communication protocols. Configuration data is stored in the module defining which program is to be transferred from the memory cartridge into the shared memory of each port circuit. Protocol parameter configuration inquiries are stored for each program so that the user can be queried to select values for the parameters of the communication protocol used by the program.” See Abstract.
U.S. Pat. No. 5,991,510 (Beaulieu) allegedly cites “A robot drive has operating and configuration parameters at an installation location stored in an easily removable storage device on the drive, or nearby, so that special data, such as that associated with arm design and system layout, including taught stations, can remain associated with the drive and installation whereby the drive system can be installed or replaced in minimal time since the storage device does not need reprogramming. This removable storage device, in the form of a static memory or Master Key, e.g., a Dallas Key or E Prom or the like, may be affixed to the robot body or off board nearby, and may store arm design parameters, programmed while on the robot body or off-line, and becomes a unique part structured for manufacturing with respect to the arm set design. Further, nominal system layout parameters can be prestored in the Key, and when this Key is affixed to the robot drive, the robot automatically has the information regarding both arm design and system layout, which will help avoid collisions and provide a starting point for the fine teaching of the transfer stations. Additionally, the fine location parameters for each transfer station may be stored in the Key when the robot is installed. Thus, the Key will contain all the information needed to make a robot unique to a unique system, and when a robot drive is replaced, by affixing the original Key to the new robot or nearby, it will assume all of the parameters of the initial robot.” See Abstract.
U.S. Pat. No. 4,937,419 (Kolodziej) allegedly cites “[a] programmable weld and machine controller for use in controlling a welding machine. The controller includes a central processing unit containing a stored control program connected to a memory which operates both the welding operation of the machine as well as the operation of the machine itself. The controller receives inputs from the machine in its various operational states as well as a data entry and display unit and a current monitor of the welding operation which generates outputs through a heat controlled output to activate a firing circuit to control the welding operation. Back-up of the memory program may be attained through an accessory port to a memory back-up storage unit.” See Abstract.